Mystery Powders

Students study physical and chemical properties and changes while conducting an investigation to identify white mystery powders. The plan includes an overview, key concepts with outcomes, vocabulary with definitions, a materials list, and step by step directions for conducting the investigation and assessment ideas. This lesson lends itself to differentiation in that students can work individually, with partners, or in small groups to perform various tests to identify mystery powders. The mystery powders are common household items such as detergent, baking soda, sugar, and cornstarch. Students will experience chemical and physical changes and properties as they perform tests on the powders. Students conduct solubility, iodine, vinegar and heat tests. Information is provided about results from each test to assist in the identification of the powders. Five sessions should be set aside for students to complete the lesson. Assessments include a vocabulary quiz, completed data collection, an explanation of chemical and physical changes and a drawing of each powder as seen under a microscope.

Weblink address (URL): 
Mystery Powders

Standards & Objectives

Learning objectives: 

Key Concepts:

  • Students will learn that a physical change happens when some properties change (such as shape), but the material itself is the same before and after the change. The change can be undone.
  • Students will learn that a chemical change occurs when a substance present at the beginning of the change are not present at the end; new substances are formed. The change cannot be undone.

Lesson Variations

Blooms taxonomy level: 
Understanding

Helpful Hints

Materials Needed:

  • 3 pounds salt 
  • 5 pounds sugar 
  • 4 pounds baking soda 
  • 4 pounds cornstarch 
  • 5 pounds plaster of paris 
  • Small clear cups 
  • Post-it notes 
  • Wooden stir sticks 
  • Dropper bottles 
  • Recording sheets 
  • Mystery Powders Mixtures sheets 
  • Science notebooks and pencils 
  • Toothpicks 
  • Heat source: hot plate, candles, or Sterno 
  • Wooden clothespin 
  • Hand lenses 
  • Spoons 
  • Iodine 
  • Water 
  • Safety Goggles 
  • Vinegar 
  • Newspaper 
  • Sponges 
  • Paper towels

References

Contributors: 
Diane Vaughn
Originator: 
Ayers Institute for Learning & Innovation